Gas turbine plant



Jan. 8, 1946. w. TRAUPEL 2,392,622

GAS TURB INE PLANT Filed May 25, 1945 3 Sheets-Sheet 1 ATTO R NEYS Jan. 8, 1946. w. TRAUPEL 2,392,622

GAS TURBINE PLANT Filed May 25, 1945 3 Sheets-Sheet 2 INVENTOR Wake) 7744,06! BY ATT O R N E Y5 Jan. 8, 1946. w TRAUPEL 2,392,622

GAS TURBINE PLANT Filed May 25, 1943 3 Sheets-Sheet I5 INVENTOR Wail Tiara 0e! Patented Jan. 8, 1946 GAS TURBINE PLANT Walter Traupel, Wlnterthur, Switzerland, aimor to Sulzer Frerel, Societe Anonyme, Winterthnl', Switzerland Application May 25, 1943, Serial No. 488,402 In Switzerland AP! 18. 1942 4 Claims.

The invention relates to a gas turbine plant in which a working medium in a circuit is compressed by a compressor, then heated in a heat exchanger by the combustion gases from a combustion chamber, and thereupon expanded in a turbine driving the compressor, a part of the working medium being withdrawn from the circuit and led as combustion air to the combustion chamber from which the combustion gases are passed first to said heat exchanger and then into a turbine producing the work delivered outside the plant. Accordingly two kinds of working media are taken from the heat exchanger which is constructed as a gas heater, first the working medium which receives heat through heat exchange and operates the turbine driving the compressor, and secondly the working medium heated dlrectby combustion and led in the form of combustion gases to the turbine producing the work delivered outside the plant. In order to be able to maintain an uninterrupted service, it must be possible to regulate separately, and independently from each other, the working of the two turbines and thereby also the condition (state) or the two working media. This task is solved by the invention in that the part of the circuit situated between the compressor and the heat exchanger is connected by piping containing an adjusting device to the part of the circuit situated between the heat exchanger and the turbine driving the compressor. Through this adjustable piping a greater or small er part or the working medium flowing round in the closed circuit can be diverted irom the heatexchange surface of the gas heater, and in this manner the quantity of heat transferred from one working medium to the other can be regulate-d in accordance with requirements. It is thus possible to keep at a suitable height, and separate from each other, on the one hand the temperature oi. the combustion gases passing to the turblne producing the work delivered outside the plant, and on the other hand the temperature of the air passing into the compressor turbine.

The plant may be simplified to a certain extent it the adjusting device in the piping connecting the two parts of the circuit is not opened until the temperature of the working medium entering the compressor turbine exceeds a limiting value lying above the normal service temperature of that turbine.

The invention is explained more in detail with the help of the drawings.

Fig. 1 shows diagrammatically a gas turbine plant according to the invention.

Fig. 2 illustrates separate details of the regulating device of the plant according to Fig. 1.

Fig. 3 shows a regulating device designed in accordance with other considerations.

The low-pressure compressor i (Fig. 1) draws air from the pipe I and delivers it through the intermediate cooler I to the high-pressure compressor 4. The compressed air passes through the tubes I 01' the heat-exchanger I into the pipe I. A part of the heated air flows through the space surrounding the tubes I in the air heater I and then through the pipe II into the turbine ll. After expanding in that turbine, the air flows through the space surrounding the tubes I in the heat exchanger I, and then through the cooler I2 and the pipe 2 back into the compressor I.

From the pipe I a certain quantity of the air is extracted through the pipe II and led to the burner II of the air heater 9. The combustion gases flow through the tubes 8 of the air heater and pass into the turbine II which produces useful work. To replace the air extracted from the circuit, air is again supplied to it through the compressor ll. This replaced air comes into the circuit at an intermediate place in the heat exchanger 8 and at once gives u a part of its heat of compression to the air flowing in the circuit. Consequently there is no closed circuit, in so far that a quantity oi working medium is continually being extracted from the plant and 9. corresponding quantity being supplied in its place.

The air turbine ii and the compressors l, I and I! have one shaft in common and are of such dimensions that the output of the turbine is equal to the power required for driving the compressors. The turbine It to which the combustion gases are led drives the propeller I! through the gear II.

To regulate the temperature of the air flowing into the turbine II a bypass pipe 20 is provided, through which a part of the air not yet heated is led past the air heater I and mixed at place II with the already heated air. For adjusting the quantity of bypassed air, a regulating member 22 is provided, which is controlled through the impulse pipe 23 by the thermostat II in accordance with the temperature or the mixture at place 2!, so that temperature fluctuations in the air flowing into the turbine l I are at least diminished.

The replaced air led into the air circuit can be adjusted by means 01' the valve 25, and the quantity of fuel led to the air heater I can be adjusted by the regulating valve II arranged in the fuel pipe 21, both adjustments being made in accordance with the prevailing load conditions. By means of the adiustment of the replace quantity,

the pressure level or, in other words, the degree supercharging of the air circuit, is suited to the load on the turbine ll producing useful work. The quantity of fuel is then adjusted in accordance with the degree of supercharging. The regulating device 222l can be set in such a way that it allows air to be bypassed round the air heater 9 only when a temperature above the normal service temperature is exceeded.

The air flowing through the pipe Ill (Figs. 1 and 2) influences the thermostat 24 (Fig. 2), which is designed as an enclosed container partl v filled with liquid. According to the changing temperature of the air flowing through the pipe ill, this liquid will be under a higher or a lower evaporating pressure. In accordance with the changes in the evaporating pressure, the bellows 28 will be more or less pressed out in the direction of the double arrow 28.

The movements of expansion or the bellows 28 are transmitted to the valve I2 through the lever 30 and the linkage 3|. The lever III is also connected to the rod 83 of a hydraulic dash-pot control 34, which comes into action as a loose return motion. The dash-pot control device is connected through the rod to the piston II or the servomotor I! and through the rod III to the valve 3! oi the regulating member 22 in the pipe 20.

An increase in the air temperature at the spot 2| in the pipe Ill causes an increase in pressure in the bellows 28. so that the lever 30 moves at its joint I in the plus direction of the arrow 29 and the rod 3| and the valve 82 in the plus direction of the arrow 4|. Liquid under pressure then passes from the pipe 42 through the pipe 44 and under the piston 38, which is moved in the plus direction of the arrow 45. The liquid forced out from the upper side of the piston 36 can flow away through the pipe 46.

The valve 39 of the regulating member 22 is moved by the servomotor piston 38 in the lus direction of the arrow 45.. The cross-sectional area of flow through the regulating member is increased, and by introducing a greater quantity of as through the bypass the temperature of the mixed gases at place 2| in the pipe Ill is ain reduced to the desired figure.

Through the dash-pot ll, in the described regulating process the lever iii is first of all moved at its joint 41 against the spring 48 in the plus direction of the double arrow .9, whereby the displacement of the control valve 32 that starts the regulating action is again reversed. Since the servomotor piston 36 and the return-motion rod 33 are loosely connected to each other through the dash-pot, the regulating process will come to rest only when the springs 48 and i0 balance each other, and the control valve 32 closes both the pipe 44 and the pipe it. But such a position is only possible at one and the same nominal temperature, which has been set as desired. The regulating device therefore acts isothermally; it brings the temperature always back to the same desired fi re.

If the temperature oi the mixed gases falls at place II, a similar regulating process takes place, but with the regulating motions in the opp site direction. The cross-sectional area of flow through the regulating member 22 is diminished and the temperature 01' the mixed gases is thereby brought to its original nominal figure.

Fig. 3 shows a regulating device by which nonheated air is bypassed round the heater only temporarilyduring fluctuations of load, particular- 1y during drops in the load. A thermostat 24 and also a pressurestat II are influenced by the air in the pipe II. The bellows 28 of the thermostat moves the cam 52 in the directions of the double arrow Bl round the fixed pivot point 64.

The inverted T lever 58, pivoted at the fixed point it, is held pressed through its roller 58 against the curved path of the cam 52 by means of the spring 61. The joint I! of the T lever influences the control valve 32 through the link Ii, the lever 6i and the link 3i. By means oi the rod 38, the piston 38 or the servomotor I1 adjusts the valve ll of the regulating member 22 in the bypass pipe 2|.

At the joint I: of the T lever 58 is linked the lever 68 which is connected at the joint 84 to the pressurestat SI and at the joint 65 to the valve 6 of the fuel regulating member 28.

It the temperature of the mixed gases rises at place 2i in the pipe ll, the bellows 28 expands in the plus direction 01' the double arrow 28 and moves the path of the cam 52 in the plus direction of the arrow ll. Thereby the T lever 58 moves in the plus direction of the arrow 61 and consequently the link iii in the plus direction of the arrow 68. When the link Bil comes into contact with the lever 8| at place is, the control valve 32 is raised by the link 3!. From the pipe 4! liquid under pressure then passes through the pipe 44 into the servomotor 31 and moves the piston 36 and the valve 38 in the plus direction oi the arrow 45. Thereby the cross-sectional area of flow through the regulating member 22 is increased.

At the same time the lever II is pushed at the joint 41 in the plus direction 01' the arrow 45, so that the pivot point III, the link 3| and the valve 32 are moved in the minus direction of the arrow ll, thus counteracting the motion introducing the regulating process. Because of the increased, non-heated quantity or air introduced through the pipe 2|] into the heated quantity of air, the rising of the temperature of the mixed gases at place 2|, which initiates the regulating operation, is again neutralised andthe temperature is brought back to the normal desired figure.

During the regulating operation described above, the joint 82 pushes the lever Bl in the plus direction of the double arrow ll, so that the joint 65, the lever 83 and the valve 6 of the fuel regulating member are pushed in the minus direction of the arrow 12. Thereby also the quantity of fuel introduced to the burner of the air heater through the pipe 2! is reduced. The increasing of the temperature of the mixed gases at place II in the pipe I not only allows a greater quantity of cold air to flow into the pipe it through the pipe 20, but at the same time diminishes the quantity of fuel led to the burner of the air heater.

The pressurestat II has a piston I3 which is pressed to a greater or less extent in the positive direction of the double arrow 1| against the spring II. When the air pressure increases, the joint 84 of the lever 63 is moved in the plus direction, thereby moving the valve 88 in the plus direction or the arrow 12. The cross-sectional area of flow of the fuel regulating member 26 is thereby increased and a greater quantity 0! fuel is led to the burner 01' the air heater.

When the air pressure in the pipe it decreases, the valve 0 is moved in the minus direction or the arrow 12, thereby reducing the quantity of fuel introduced to the air heater. The regulating member 22 in the bypass pipe 20 cannot be aflected by the pressurestat I I The play between the point 89 of the lever ii and the rod 88 is, in conjunction with the shape of the cam 82 and the influencing of the fuel regulating member 28 by pressure and temperature, chosen in such a way that the valve 39 of the regulating member 22 opens only when a rise in temperature because of the heat stored in the exchange surfaces cannot be prevented even by reducing the quantity of fuel introduced. when the influence of the stored heat has been removed, the valve 39 will be closed again.

The invention can also be adopted when a gas other than air is heated in the heat exchanger. The important point is that the bypassing of cold working medium to the side of the heat transmitting medium takes place at a low temperature.

I claim:

1. A gas turbine plant which comprises at least one compressor, a first turbine for driving the compressor, a combustion heater, a power turbine for driving an outside load, a conduit for passing a part of the compressed air gas from the compressor through the heater to the first turbine, another conduit for passing another part of the compressed air into the heater for use as combustion air. the combustion gases passins in heat exchange contact with the compressed gas air passing through the heater to the first turbine, a bypass pipe for by-passing a part of the compressed air around the heater and into the first turbine, a valve for controlling the fiow of air through the by-pass, and means responsive to the temperature of the air entering the first turbine for operating the valve in the by-pass.

2. A gas turbine plant according to claim 1 which comprises means responsive to the pressure and other means responsive to the temperature of the air entering the first turbine to control the operation of the valve in the by-pass.

3. A gas turbine plant according to claim 1 which comprises fuel supply means for the heater, means responsive to the pressure and the temperature of the air entering the first turbine to actuate the valve in the by-pass and the fuel supply means.

4. A gas turbine plant which comprises a first turbine, a high pressure compressor and a low pressure compressor each driven by the first turbine, means for passing compressed make-up gas into the low pressure compressor, a heat exchanger, means for passing expanded gas from the first turbine through the heat exchanger to mix with the make-up gas and enter the lowpressure compressor, means for passing the compressed gas from the high-pressure compressor through the heat exchanger in heat exchange contact with the make-up gas and expanded gas from the first turbine, a combustion heater, a power turbine for driving an outside load, a conduit for passing a part of the compressed gas from the compressor through the heater to the first turbine, another conduit for passing another part of the compressed gas into the heater for use as combustion gas, the combustion gases passing in heat exchange contact with the compressed gas passing through the heater to the first turbine, a by-pass pipe for by-passing a part of the compressed gas around the heater andlnto the first turbine, a valve for controlling the fiow of gas through the by-pass, and means responsive to the temperature of the gas entering the first turbine for operating the valve in the by- CERTIFICATE OF CORRECTION.

Patent No. 2,592,622.

January 8, 1914.6.

WALTER TRAUPEL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, lines 25 and 31, claim 1, strike out the word "gas"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of April, A. D. 19146.

(Seal) Leslie Frazer First Assistant Commissioner of Patentsing member 22 in the bypass pipe 20 cannot be aflected by the pressurestat I I The play between the point 89 of the lever ii and the rod 88 is, in conjunction with the shape of the cam 82 and the influencing of the fuel regulating member 28 by pressure and temperature, chosen in such a way that the valve 39 of the regulating member 22 opens only when a rise in temperature because of the heat stored in the exchange surfaces cannot be prevented even by reducing the quantity of fuel introduced. when the influence of the stored heat has been removed, the valve 39 will be closed again.

The invention can also be adopted when a gas other than air is heated in the heat exchanger. The important point is that the bypassing of cold working medium to the side of the heat transmitting medium takes place at a low temperature.

I claim:

1. A gas turbine plant which comprises at least one compressor, a first turbine for driving the compressor, a combustion heater, a power turbine for driving an outside load, a conduit for passing a part of the compressed air gas from the compressor through the heater to the first turbine, another conduit for passing another part of the compressed air into the heater for use as combustion air. the combustion gases passins in heat exchange contact with the compressed gas air passing through the heater to the first turbine, a bypass pipe for by-passing a part of the compressed air around the heater and into the first turbine, a valve for controlling the fiow of air through the by-pass, and means responsive to the temperature of the air entering the first turbine for operating the valve in the by-pass.

2. A gas turbine plant according to claim 1 which comprises means responsive to the pressure and other means responsive to the temperature of the air entering the first turbine to control the operation of the valve in the by-pass.

3. A gas turbine plant according to claim 1 which comprises fuel supply means for the heater, means responsive to the pressure and the temperature of the air entering the first turbine to actuate the valve in the by-pass and the fuel supply means.

4. A gas turbine plant which comprises a first turbine, a high pressure compressor and a low pressure compressor each driven by the first turbine, means for passing compressed make-up gas into the low pressure compressor, a heat exchanger, means for passing expanded gas from the first turbine through the heat exchanger to mix with the make-up gas and enter the lowpressure compressor, means for passing the compressed gas from the high-pressure compressor through the heat exchanger in heat exchange contact with the make-up gas and expanded gas from the first turbine, a combustion heater, a power turbine for driving an outside load, a conduit for passing a part of the compressed gas from the compressor through the heater to the first turbine, another conduit for passing another part of the compressed gas into the heater for use as combustion gas, the combustion gases passing in heat exchange contact with the compressed gas passing through the heater to the first turbine, a by-pass pipe for by-passing a part of the compressed gas around the heater andlnto the first turbine, a valve for controlling the fiow of gas through the by-pass, and means responsive to the temperature of the gas entering the first turbine for operating the valve in the by- CERTIFICATE OF CORRECTION.

Patent No. 2,592,622.

January 8, 1914.6.

WALTER TRAUPEL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, lines 25 and 31, claim 1, strike out the word "gas"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of April, A. D. 19146.

(Seal) Leslie Frazer First Assistant Commissioner of Patents- 

